Modified polyphenylene ether-polyamide compositions and process

ABSTRACT

Novel modified polyphenylene ether-polyamide compositions comprising polyphenylene ether, polyamide and a polycarboxylic acid and the reaction product thereof and an improved process for preparing the same.

This is a continuation of Ser. No. 08/068,275 filed on May 25, 1993, nowabandoned, which is a continuation of Ser. No. 07/965,042, filed on Oct.22, 1992, now abandoned, which is a continuation of Ser. No. 07/620,434,filed on Nov. 30, 1990, now abandoned, which is a continuation of Ser.No. 07/168,713, filed on Mar. 16, 1988, now abandoned, which is adivisional of Ser. No. 06/736,489, filed on May 20, 1985, now abandoned,which is a continuation-in-part of Ser. No. 06/612,369, filed on May 21,1984, also now abandoned.

The present invention relates to modified polyphenylene ether-polyamidecompositions having improved chemical resistance, processability,elongation properties and/or impact strength as compared to unmodifiedcompositions. More specifically, it relates to a resin composition whichcomprises a combination and/or the reaction product of a) one or morepolyphenylene ether resins, b) one or more polyamide resins and c) atleast one aliphatic polycarboxylic acid or derivative modifier.

The invention also relates to an improved process for the manufacture ofsaid modified polyphenylene ether-polyamide compositions wherein theimprovement comprises precompounding the aliphatic polycarboxylic acidmodifier with either the polyamide or, preferably, the polyphenyleneether prior to compounding with the other polymer. Such precompoundingunexpectedly results in improved physical properties in the finalcomposition over those prepared from the same ingredients withoutprecompounding. Inasmuch as the compositions of the present inventionmay further comprise impact modifiers, reinforcing agents, stabilizersand the like, these may also be precompounded with either of thepolymers for improved properties.

The polyphenylene ether resins are characterized by a unique combinationof chemical, physical and electrical properties over a temperature rangeof more than 600° F., extending from a brittle point of about -275° F.to a heat distortion temperature of about 375° F. This combination ofproperties renders the polyphenylene ethers suitable for a broad rangeof applications. However, in spite of the aforementioned beneficialproperties, the usefulness of the polyphenylene ether resins is limitedas a consequence of their poor processability, impact resistance andchemical resistance.

Finholt (U.S. Pat. No. 3,379,792) discloses polymer blends wherein theprocessability of polyphenylene ether resins may be improved by blendingtherewith from 0.1 to 25% by weight of a polyamide. However, theadvantages of the Finholt invention are limited by the fact that whenthe concentration of the polyamide exceeds 20% by weight, appreciablelosses in other physical properties result. Specifically, there is no,or at best poor, compatibility between the polyphenylene ether and thepolyamide such that phase separation of the resins occurs on molding orthe molded article is inferior in mechanical properties.

Ueno et al (U.S. Pat. No. 4,315,086) discloses polyphenylene etherblends having improved chemical resistance without a loss of othermechanical properties by blending therewith a polyamide and a specificcompound selected from the group consisting essentially of A) liquiddiene polymers, B) epoxy compounds and C) compounds having in themolecule both of i) an ethylenic carbon-carbon double bond orcarbon-carbon triple bond and ii) a carboxylic acid, acid anhydride,acid amide, imide, carboxylic acid ester, amino or hydroxyl group.

Finally, Kasahara et al (EP46040) discloses the use of a copolymercomprising units of a vinyl aromatic compound and either an alpha,beta-unsaturated dicarboxylic acid anhydride or an imide compoundthereof as a modifier to an impact resistant polyphenyleneether-polyamide blend for improved heat resistance and oil resistance.

Applicants have now discovered novel polyphenylene ether polyamideblends having improved impact strength, elongation, chemical resistance,processability and/or heat resistance as well as reduced waterabsorption as compared to unmodified polyphenylene ether-polyamidecompositions. Specifically, applicants have discovered novel resincompositions having the aforementioned properties comprising acombination of and/or the reaction product of a polyphenylene ether, apolyamide and a property improving amount of a) an aliphaticpolycarboxylic acid or derivative thereof represented by the formula:

    (R.sup.I O).sub.m R(COOR.sup.II).sub.n (CONR.sup.III R.sup.IV).sub.s

wherein R is a linear or branched chain, saturated aliphatic hydrocarbonof from 2 to 20, preferably 2 to 10, carbon atoms; R^(I) is selectedfrom the group consisting of hydrogen or an alkyl, aryl, acyl orcarbonyl dioxy group of 1 to 10, preferably 1 to 4 carbon atoms, mostpreferably hydrogen; each R^(II) is independently selected from thegroup consisting of hydrogen or an alkyl or aryl group of from 1 to 20carbon atoms, preferably from 1 to 10 carbon atoms; each R^(III) andR^(IV) is independently selected from the group consisting essentiallyof hydrogen or an alkyl or aryl group of from 1 to 10, preferably from 1to 6, most preferably 1 to 4, carbon atoms; m is equal to 1 and (n+s) isgreater than or equal to 2, preferably equal to 2 or 3, and n and s areeach greater than or equal to zero and wherein (OR^(I)) is alpha or betato a carbonyl group and at least two carbonyl groups are separated by 2to 6 carbon atoms. Further, these compositions may contain stabilizingand/or property improving amounts of primary or secondary amines.Optionally, the compositions of the present invention may furthercomprise fillers as well as other property enhancing additives such aspolymeric impact modifiers and/or inorganic reinforcing additives and/orother polymers including alkenyl aromatic polymers such as the styrenicpolymers.

Additionally, applicants have now discovered an improved process for thepreparation of the said polyphenylene ether-polyamide blends.Specifically, while most any known process for the preparation of blendcompositions, e.g., melt blending, may be employed in the preparation ofthe compositions of the present invention, applicants have surprisinglyfound further enhancement in impact strength, elongation, processabilityand the like by precompounding the aliphatic polycarboxylic acidmodifier with either of the polyphenylene ether or polyamide resinsprior to compounding with the other. Said precompounding steps may alsobe applied with respect to any additional additives employed in thepreparation of the compositions.

Although the exact physical configuration of the compositions of thepresent invention is not known, it is generally believed that thecompositions comprise a dispersion of one polymer in the other.Applicants believe the likely configuration is wherein the polyphenyleneether is dispersed in a polyamide matrix, however, the inverse may alsobe possible particularly where the polyamide is present in only a minoramount. Applicants also contemplate that there may be present in theproducts produced hereby some graft polyphenylene ether-polyamideproducts. Furthermore, applicants contemplate that grafting, if present,may be such that the polycarboxylic acid may, at least in part, promotegrafting and/or act as a graft-linking agent itself. Thus, all suchdispersions as well as graft, partially grafted and non-grafted productsare within the full intended scope of the invention.

The polyphenylene ethers suitable for use in the practice of the presentinvention are well known in the art and may be prepared by any of anumber of catalytic and non-catalytic processes from correspondingphenols or reactive derivatives thereof. Examples of polyphenyleneethers and methods for their production are disclosed in U.S. Pat. Nos.3,306,874; 3,306,875; 3,257,357; 3,257,358; 3,337,501 and 3,787,361, allincorporated herein by reference. For brevity, the term "polyphenyleneether" as used throughout this specification and the appended claimswill include not only unsubstituted polyphenylene ether (made fromphenol) but also polyphenylene ethers substituted with varioussubstituents. The term also includes polyphenylene ether copolymers,graft copolymers and block copolymers of alkenyl aromatic compounds,especially vinyl aromatic compounds, as disclosed below, and apolyphenylene ether.

Suitable phenol compounds for the preparation of the polyphenyleneethers may be represented by the general formula: ##STR1## wherein eachQ is a monovalent substituent individually selected from the groupconsisting of hydrogen, halogen, aliphatic and aromatic hydrocarbon andhydrocarbonoxy radicals free of a tertiary alpha-carbon atom andhalohydrocarbon and halohydrocarbonoxy radicals free of a tertiaryalpha-carbon atom and having at least two carbon atoms between thehalogen atom and the phenyl nucleus, and wherein at least one Q ishydrogen.

As specific examples of the phenol compound represented by the aboveformula, there may be given phenol; o-, m- and p- cresols; 2,6, 2,5, 2,4and 3,5 dimethylphenols; 2-methyl-6-phenyl-phenol; 2,6-diphenylphenol;2,6-diethylphenol; 2-methyl-6-ethylphenol; and 2,3,5-, 2,3,6- and2,4,6-trimethylphenols. Two or more phenol compounds may be used incombination should copolymers be desired. Additionally, copolyphenyleneethers may also be prepared from a phenol compound of the above generalformula with a phenol compound not represented by the above generalformula including, for example, a dihydric phenol such as bisphenol-A,tetrabromobisphenol-A, resorcinol or hydroquinione.

Illustrative of suitable polyphenylene ethers there may be given, forexample, poly(2,6 dimethyl-1,4-phenylene)ether;poly(2-methyl-1,4-phenylene) ether, poly(3-methyl-1,4-phenylene)ether;poly(2,6-diethyl-1,4-phenylene)ether;poly(2-methyl-6-allyl-1,4-phenylene)ether;poly(2,6-dichloromethyl-1,4-phenylene)ether;poly(2,3,6-trimethyl-1,4-phenylene) ether; poly(2,3,5,6-tetramethylphenylene)ether; poly(2,6-dichloro-1,4-phenylene)ether;poly(2,6-diphenyl-1,4-phenylene)ether;poly(2,6-dimethyl-1,4-phenylene)ether and the like. Further, asmentioned above, copolymers of the phenol compounds may also be used.

Preferred polyphenylene ethers will have the formula: ##STR2## where Qis as defined above and n is at least 50, preferably from about 50 toabout 200. Examples of polyphenylene ethers corresponding to the aboveformula can be found in the above referenced patents and include, amongothers: poly(2,6-dilauryl-1,4-phenylene)ether;poly(2,6-diphenyl-1,4-phenylene)ether;poly(2,6-dimethyoxy-1,4-phenylene)ether;poly(2,6-diethoxy-1,4-phenylene)ether;poly(2-methoxy-6-ethyoxy-phenylene)ether;poly(2-ethyl-6-stearyloxy-1,4-phenylene)ether;poly(2,6-dichloro-1,4-phenylene)ether;poly(2-methyl-6-phenyl-1,4-phenylene)etherpoly(2,6-dibenzyl-1,4-phenylene)ether;poly(2-ethoxy-1,4-phenylene)ether; poly(2-chloro-1,4-phenylene)ether;poly(2,6-dibromo-1,4-phenylene)ether; and the like.

For the purpose of the present invention, an especially preferred familyof polyphenylene ethers include those having a C₁ to C₄ alkylsubstitution in the two positions ortho to the oxygen ether atom.Illustrative members of this class are:poly(2,6-dimethyl-1,4-phenylene)ether;poly(2,6-diethyl-1,4-phenylene)ether;poly(2-methyl-6-ethyl-1,4-phenylene)ether;poly(2,6-dipropyl-1,4-phenylene)ether;poly(2-ethyl-6-propyl-1,4-phenylene)ether; and the like; most preferablypoly(2,6-dimethyl-1,4-phenylene)ether.

One method for the production of the above polyphenylene ethers is bythe oxidation of a phenol compound by oxygen or an oxygen-containing gasin the presence of a catalyst for oxidative coupling. There is noparticular limitation as to the choice of catalysts and any catalystsfor oxidation polymerization can be employed. As typical examples of thecatalyst, there may be given a catalyst comprising a cuprous salt and atertiary amine and/or secondary amine, such as cuprouschloride-trimethylamine and dibutylamine, cuprous acetate-triethylamineor cuprous chloride-pyridine; a catalyst comprising a curpic salt, atertiary amine, and an alkali metal hydroxide, such as cupricchloride-pyridine-potassium hydroxide; a catalyst comprising a manganesesalt and a primary amine, such as manganese chloride-ethanolamine ormanganese acetate-ethylenediamine; a catalyst comprising a manganesesalt and an alcoholate or phenolate, such as manganese chloride-sodiummethylate or manganese chloride-sodium phenolate; and a catalystcomprising a cobalt salt and a tertiary amine.

Polyamides suitable for the preparation of the compositions of thepresent invention may be obtained by polymerizing amonoamino-monocarboxylic acid or a lactam thereof having at least 2carbon atoms between the amino and carboxylic acid group; or bypolymerizing substantially equimolar proportions of a diamine whichcontains at least 2 carbon atoms between the amino groups and adicarboxylic acid; or by polymerizing a monoaminocarboxylic acid or alactam thereof as defined above together with substantiallyequimolecular proportions of a diamine and a dicarboxylic acid. Thedicarboxylic acid may be used in the form of a functional derivativethereof, for example an ester or acid chloride.

The term "substantially equimolecular" proportions (of the diamine andof the dicarboxylic acid) is used to cover both strict equimolecularproportions and slight departures therefrom which are involved inconventional techniques for stabilizing the viscosity of the resultantpolyamides.

Examples of the aforementioned monoamino-monocarboxylic acids or lactamsthereof which are useful in preparing the polyamides include thosecompounds containing from 2 to 16 carbon atoms between the amino andcarboxylic acid groups, said carbon atoms forming a ring with the--CO--NH-- group in the case of a lactam. As particular examples ofaminocarboxylic acids and lactams there may be mentioned ε-aminocaproicacid, butyrolactam, pivalolactam, caprolactam, capryl-lactam,enantholactam, undecanolactam, dodecanolactam and 3- and 4-aminobenzoicacids.

Diamine suitable for use in the preparation of the polyamides includethe straight chain and branched, alkyl, aryl and alkyl-aryl diamines.Such diamines include, for example, those represented by the generalformula:

    H.sub.2 N(CH.sub.2).sub.n NH.sub.2

wherein n is an integer of from 2 to 16, such as trimethylenediamine,tetramethylenediamine, pentamethylenediamine, octamethylenediamine andespecially hexamethylenediamine, as well as trimethyl hexamethylenediamine, meta-phenylene diamine, meta-xlylene diamine and the like.

The dicarboxylic acids may be aromatic, for example isophthalic andterephthalic acids. Preferred dicarboxylic acids are of the formula

    HOOC--Y--COOH

wherein Y represents a divalent aliphatic group containing at least 2carbon atoms, and examples of such acids are sebacic acid,octadecanedoic acid, suberic acid, glutaric acid, pimelic acid andadipic acid.

Typical examples of the polyamides or nylons, as these are often called,include for example polyamides 6, 6/6, 11, 12, 6/3, 6/4, 6/10 and 6/12as well as polyamides resulting from terephthalic acid and/orisophthalic acid and trimethyl hexamethylene diamine, polyamidesresulting from adipic acid and meta xylylenediamines, polyamidesresulting from adipic acid, azelaic acid and.2,2-bis-(p-aminocyclohexyl)propane and polyamides resulting fromterephthalic acid and 4,4'-diamino-dicyclohexylmethane. Mixtures and/orcopolymers of two or more of the foregoing polyamides or prepolymersthereof, respectively, are also within the scope of the presentinvention. Preferred polyamides are the polyamides 6, 6/6, 11 and 12,most preferably polyamide 6/6.

It is also to be understood that the use of the term "polyamides" hereinand in the appended claims is intended to include the toughened or supertough polyamides. Super tough polyamides, or super tough nylons, as theyare more commonly known, are available commercially, e.g. from E.I.dupont under the tradename Zytel ST, or may be prepared in accordancewith a number of U.S. Patents including, among others, Epstein--U.S.Pat. No. 4,174,358; Novak--U.S. Pat. No. 4,474,927; Roura--U.S. Pat. No.4,346,194; and Joffrion--U.S. Pat. No. 4,251,644, herein incorporated byreference. These super tough nylons are prepared by blending one or morepolyamides with one or more polymeric or copolymeric elastomerictoughening agents. Suitable toughening agents are disclosed in theabove-identified U.S. Patents as well as in Caywood, Jr.--U.S. Pat. No.3,884,882 and Swiger, U.S. Pat. No. 4,147,740 and Gallucci et el.,"Preparation and Reactions of Epoxy-Modified Polyethylene", J. APPL.POLY. SCI., V. 27, pp. 425-437 (1982) herein incorporated by reference.Typically, these elastomeric polymers and copolymers may be straightchain or branched as well as graft polymers and copolymers, includingcore-shell graft copolymers, and are characterized as havingincorporated therein either by copolymerization or by grafting on thepreformed polymer, a monomer having functional and/or active or highlypolar groupings capable of interacting with or adhering to the polyamidematrix so as to enhance the toughness of the polyamide polymer.

The blending ratio of polyphenylene ether to polyamide is 5 to 95% bywt. preferably 30 to 70% by wt. of the former to 95 to 5% by wt.,preferably 70 to 30% by wt. of the latter. When the polyamide is lessthan 5 wt. percent, its effect to improve solvent resistance is small,while when it exceeds 95 wt. percent, thermal properties such as heatdistortion temperature tend to become poor.

Compounds useful for improving the physical properties of thepolyphenylene ether-polyamide compositions are aliphatic polycarboxylicacids and derivatives thereof represented by the formula:

    (R.sup.I O).sub.m R(COOR.sup.II).sub.n (CONR.sup.III R.sup.IV).sub.s

wherein R is a linear or branched chain, saturated aliphatic hydrocarbonof from 2 to 20, preferably 2 to 10, carbon atoms; R^(I) is selectedfrom the group consisting of hydrogen or an alkyl, aryl, acyl orcarbonyl dioxy group of 1 to 10, preferably 1 to 6, most preferably 1 to4, carbon atoms, especially preferred is hydrogen; each R^(II) isindependently selected from the group consisting of hydrogen or an alkylor aryl group of from 1 to 20 carbon atoms, preferably from 1 to 10carbon atoms; each R^(III) and R^(IV) is independently selected from thegroup consisting essentially of hydrogen or an alkyl or aryl group offrom 1 to 10, preferably from 1 to 6, most preferably 1 to 4, carbonatoms; m is equal to 1 and (n+s) is greater than or equal to 2,preferably equal to 2 or 3, and n and s are each greater than or equalto zero and wherein (OR^(I)) is alpha or beta to a carbonyl group and atleast two carbonyl groups are separated by 2 to 6 carbon atoms.Obviously, R^(I), R^(II), R^(III) and R^(IV) cannot be aryl when therespective substituent has less than 6 carbon atoms.

In general the polycarboxylic acid modifiers suitable for use hereinencompass three classes, the polycarboxylic acids, the acid esters andthe acid amides. Thus, when used herein and in the appended claims, itis to be understood that the term "polycarboxylic acid" refers to allthese classes. Illustrative of suitable polycarboxylic acids there maybe given citric acid, malic acid, and agaricic acid; including thevarious commercial forms thereof, such as, for example, the anhydrousand hydrated acids. Illustrative of acid esters useful herein includefor example, acetyl citrate and mono- and/or di-stearyl citrates and thelike. Suitable acid amides useful herein include for exampleN,N'-diethyl citric acid amide; N,N'-dipropyl citric acid amide;N-phenyl citric acid amide; N-dodecyl citric acid amide; N,N'-didodecylcitric acid amide and N-dodecyl malic acid amide. Derivatives of theforegoing polycarboxylic acids are also suitable for use in the practiceof the present invention. Especially preferred derivatives are the saltsthereof, including the salts with amines and/preferably, the alkali andalkaline metal salts. Exemplary of suitable salts include calciummalate, calcium citrate, potasium malate and potasium citrate.

The amount of the polycarboxylic acid to be used is that amount whichmanifests property improvement, especially improved compatibility aswell as improved processability, impact strength and/or elongation, inthe polyphenylene ether-polyamide compositions. In general, the amountof polycarboxylic acid compounds used will be up to about 4%, preferablyfrom about 0.05 to about 4%, most preferably from about 0.1 to about 2%by weight based on the total composition. Although higher amounts may beused, the preparation of such compositions causes significant problemsin processing resulting in compositions having large die-swell and/ormay not give optimum property improvement. The specific amount of thepolycarboxylic acid compound to be used to achieve optimum results for agiven composition is dependent, in part, on the specific polycarboxylicacid and polymers used, the weight ratio of said polymers and theprocessing conditions.

In addition to the improved processability impact strength andelongation, many of the compositions prepared in accordance with thepresent invention manifest improvements in other physical properties andcharacteristics including for example, reduced water absorption.

The above-mentioned property improving polycarboxylic acid compound maybe used alone or in combination with a primary or secondary amine. Thepresence of the amine is found to enhance the improvement of certainphysical properties, especially brightness, when used in combinationwith various polycarboxylic acids, especially for example with malicacid. Suitable amines include those primary and secondary amines havingfrom 1 to about 20, preferably from 1 to about 10 carbon atoms.Illustrative of said suitable amines there may be given, methylethylamine, diethylamine, butylamine, dibutylamine, analine,n-octadecylamine and the like. The amount of the primary or secondaryamine to be used is generally up to about 3% by wt., preferably fromabout 0.35 to about 1% by wt..

In the practice of the present invention, it may be further desirable toadd an additional modifier resin or resin combination to further improvethe physical properties, particularly the impact strength, and/orprocessability of the composition. Such modifier resins are well knownin the art and are typically derived from one or more monomers selectedfrom the group consisting of olefins, vinyl aromatic monomers, acrylicor alkyl acrylic acids and their ester derivatives as well as conjugateddienes. Especially preferred modifier resins are the rubberyhigh-molecular weight materials including natural and syntheticpolymeric materials showing elasticity at room temperature. Suitablemodifier resins include both homopolymers and copolymers, includingrandom, block, radial block, graft and core-shell copolymers as well ascombinations thereof.

Polyolefins or olefin-based copolymer employable in the practice of thepresent invention include, among others, low density polyethylene, highdensity polyethylene, linear low density polyethylene, isotacticpolypropylene, poly(1-butene), poly(4-methyl-1-pentene),propylene-ethylene copolymers, and the like. Additional olefincopolymers include copolymers of one or more alpha olefins, particularlyethylene, with copolymerizeable monomers including for example vinylacetate, acrylic acids and alkyl acrylic acids as well as the esterderivatives thereof including for example, ethylene acrylic acid,ethylacrylate, methacrylic acid, methyl methacrylate and the like.Finally, an additional class of olefin-based copolymers suitable for useherein include the ionomer resins, which may be wholly or partiallyneutralized with metal ions.

A second class of modifier resins employable herein are those derivedfrom the vinyl aromatic monomers. These include, for example, modifiedand unmodified polystyrenes, ABS type graft copolymers; AB and ABA typeblock and radial block copolymers and vinyl aromatic conjugated dienecore-shell graft copolymers. Modified and unmodified polystyrenesinclude homopolystyrenes and rubber modified polystyrenes, such asbutadiene rubber modified polystyrene otherwise referred to as highimpact polystyrene or HIPS. Additional useful polystyrenes includecopolymers of styrene and various monomers, including for example,poly(styrene-acrylonitrile) (SAN), styrene-butadiene copolymers as wellas the modified alpha and para substituted styrenes and any of thestyrene resins disclosed in U.S. Pat. No. 3,383,435, herein incorporatedby reference. ABS type of graft copolymers are typified as comprising arubbery polymeric backbone derived from a conjugated diene alone or incombination with a monomer copolymerizable therewith having graftedthereon at least one monomer, and preferably two, selected from thegroup consisting of monoalkenyl arene monomers and substitutedderivatives thereof as well as acrylic monomers such as acrylonitrilesand acrylic and alkyl acrylic acids and their esters.

An especially preferred class of vinyl aromatic monomer derived polymerresins are the block copolymers comprising monoalkenyl arene blocks andhydrogenated, partially hydrogenated and non-hydrogenated conjugateddiene blocks and represented as AB and ABA block copolymers. Suitable ABtype block copolymers are disclosed in for example U.S. Pat. Nos.3,078,254; 3,402,159; 3,297,793; 3,265,765; and 3,594,452 and UK PatentNo. 1,264,741, all herein incorporated by reference. Exemplary oftypical species of AB block copolymers there may be given:

polystyrene-polybutadiene (SBR)

polystyrene-polyisoprene and

poly(alpha-methylstyrene)-polybutadiene.

Such AB block copolymers are available commercially from a number ofsources including Phillips under the trademark Solprene.

Additionally, ABA triblock copolymers and processes for their productionas well as hydrogenation, if desired, are disclosed in U.S. Pat. Nos.3,149,182; 3,231,635; 3,462,162; 3,287,333; 3,595,942; 3,694,523 and3,842,029, all incorporated-herein by reference.

Exemplary of typical species of triblock copolymers there may be given:

polystyrene-polybutadiene-polystyrene (SBS)

polystyrene-polyisoprene-polystyrene (SIS)

poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene) and

poly(alpha-methylstyrene)-polyisoprene-poly(alpha-methystyrene).

A particularly preferred class of such triblock copolymers are availablecommercially as CARIFLEX®, KRATON D® and KRATON G® from Shell.

A third class of modifier resins suitable for use in the instantinvention are those derived from conjugated dienes. While manycopolymers containing conjugated dienes have been discussed above,additional conjugated diene modifier resins include for examplehomopolymers and copolymers of one or more conjugated dienes includingfor example polybutadiene, butadiene-styrene copolymers,isoprene-isobutylene copolymers, chlorobutadiene polymers,butadiene-acrylonitrile copolymers, polyisoprene, and the like. Finally,ethylene-propylene-diene monomer rubbers are also intended to be withinthe full scope of the present invention. These EPDMs are typified ascomprising prodominately ethylene units, a moderate amount of propyleneunits and only a minor amount, up to about 20 mole % of diene monomerunits. Many such EPDM's and processes for the production thereof aredisclosed in U.S. Pat. Nos. 2,933,480; 3,000,866; 3,407,158; 3,093,621and 3,379,701, herein incorporated by reference.

An additional group of modifier resins employable in the instantinvention are the core-shell type graft copolymers. In general, theseare characterized as having a predominately conjugated diene rubberycore or a predominately cross-linked acrylate rubbery core and one ormore shells polymerized thereon and derived from monoalkenyl areneand/or acrylic monomers alone or, preferably, in combination with othervinyl monomers. Such core-shell copolymers are widely availablecommercially, for example, from Rohm and Haas Company under thetradenames KM-611, KM-653 and KM-330, and are described in U.S. Pat.Nos. 3,808,180; 4,034,013; 4,096,202; 4,180,494 and 4,292,233.

Also within the scope of the present invention are the core-shellcopolymers wherein an interpenetrating network of the resins employedcharacterizes the interface between the core and shell. Especiallypreferred in this regard are the ASA type copolymers available fromGeneral Electric Company and sold as GELOY™ resin and described in U.S.Pat. No. 3,944,631.

It is also to be understood that in addition to the straight polymersand copolymers described above, there may be employed such polymers andcopolymers having copolymerized therewith or grafted thereon monomershaving functional groups and/or polar or active groups. Suchfunctionalized or activated polymers and copolymers are described in theabove-mentioned Epstein, Novak, Roura, Joffrion, Caywood, Swiger andGallucci references cited above with respect to the discussion ontoughened polyamides. All of such functionalized or activated polymersand copolymers may be directly blended with the ingredients to thepresent compositions or, as described above, may be precompounded with apolyamide or polyphenylene ether. Finally, other suitable modifierresins and high molecular weight rubbery materials which may be employedin the practice of the present invention include for example thiokolrubber, polysulfide rubber, polyurethane rubber, polyether rubber (e.g.polypropylene oxide), epichlorhydric rubber, ethylene propylene rubber,thermoplastic polyester elastomers, thermoplastic ether-ester elastomersand the like.

The amount of the rubbery polymer used will be up to about 100 parts byweight, preferably from about 5 to about 50 parts by weight based on 100parts by weight of a mixture of polyphenylene ether and polyamide.However, when the amount is less than 2 parts by weight, the effect ofthe rubbery polymer to improve impact resistance is poor. When theamount is more than 100 parts by weight, the impact resistance is muchimproved, however, some loss of other physical properties may result.Thus, in the interest of balancing impact resistance and other physicalproperties, it is preferred to use less than 100 parts by weight of therubbery polymer. It is also to be understood that combinations of theabove-mentioned modifier resins may be employed and are within the fullintended scope of the present invention.

Finally, in addition to the foregoing, the polyphenylene ether-polyamideresin compositions of the present invention may further comprise otherreinforcing additives, including glass fibers, carbon fibers, mineralfillers and the like as well as various flame retardants, colorants,stabilizers and the like known to those skilled in the art.

When employed in the practice of the present invention, reinforcingadditives should be used in an amount up to no more than about 50 wt. %based on the total composition, preferably no more than about 30 wt. %.Especially preferred reinforcing additives are the filamentous andchopped glass fibers. Such glass fibers may be untreated or, preferably,treated with a silane or titanate coupling agent, and are well known inthe art and widely available from a number of manufacturers.

Suitable stabilizers for use in the practice of the present inventiongenerally include most any of the known thermal and oxidativestabilizers suitable for use with either polyamides or polyphenyleneethers. Especially preferred are those stabilizers suitable for use withpolyamides. For example, liquid phosphates and hindered phenols may beemployed as well as stabilizer packages encompassing combinations ofhindered phenols and potassium and cuprous salts.

The method for producing the resin compositions of the present inventionis not particularly limited, and the conventional methods aresatisfactorily employed. Generally, however, melt blending methods aredesirable. The time and temperature required for melt-blending are notparticularly limited, and they can properly be determined according tothe composition of the material. The temperature varies somewhat withthe blending ratio of the polyphenylene ether to polyamide, but it isgenerally within a range of 270° to 350° C. A prolonged time and/or ahigh shear rate is desirable for mixing, but the deterioration of theresin composition advances. Consequently, the time needs to bedetermined taking into account these points.

Any of the melt-blending methods may be used, if it can handle a moltenviscous mass. The method may be applied in either a batchwise form or acontinuous form. Specifically, extruders, Bambury mixers, rollers,kneaders and the like may be exemplified.

While all ingredients may be initially and directly added to theprocessing system, applicants have surprisingly found that the physicalproperties of the composition, particularly impact strength andelongation, are greatly enhanced by initially precompounding one of thepolymer resins, preferably the polyphenylene ether, with thepolycarboxylic acid prior to blending with the other polymer. Suchprecompounding may be done in two steps wherein the polycarboxylic acidand the polyphenylene ether are melt extruded to form pellets which arethen blended through extrusion with the polyamide or one can employ anextrusion apparatus or melt blending apparatus wherein the polyphenyleneether and polycarboxylic acid are fed at the throat of the screw and thepolyamide is subsequently added to the extrusion system in a downstreamfeed port. In this latter method, the polycarboxylic acid andpolyphenylene ether are melt blended and in a molten state when thepolyamide is added.

With respect to the other ingredients of the compositions, allingredients may be directly added to the processing system or certainadditives may be precompounded with each other or either polymer productblending with the other polymer. For example, as discussed above, impactmodifier or toughening agents may be precompounded with a polyamide toform a super tough polyamide. Alternatively, the polyphenylene ether maybe precompounded with the rubber polymer or other additional resin andthe polycarboxylic acid and subsequently compounded with the polyamide.Furthermore, the amine compound, if used, may be premixed and/or reactedwith a polycarboxylic acid and precompounded with a polyphenylene etherprior to compounding with a polyamide. In essence, any system ofprecompounding may be employed in the practice of the present invention;however, the tremendous and unexpected improvement and physicalproperties is most apparent when at a minimum the polycarboxylic acid isprecompounded with the polyphenylene ether. While the polycarboxylicacid may be precompounded with a polyamide, the enhancement and physicalproperties is not as great.

The following examples are presented in order that those skilled in theart may better understand how to practice the present invention. Theseexamples are merely presented by way of illustration and are notintended to limit the invention thereto. Unless otherwise stated, allformulations are expressed in terms of parts by weight.

EXAMPLES 1 AND 2

A series of polyphenylene ether-polyamide compositions within andoutside of the scope of the present invention were prepared. Allcompositions were prepared on a single screw extruder by direct additionof ingredients and extruded at 300° C. The specific composition and thephysical properties thereof are shown in Table 1

                  TABLE 1                                                         ______________________________________                                        Example         A          1      2                                           ______________________________________                                        polyphenylene ether.sup.a                                                                     70         70     70                                          polyamide 6,6.sup.b                                                                           30         30     30                                          citric acid (anhydrous)                                                                       --         1.0    --                                          malic acid      --         --     1.0                                         Unnotched Izod (ft.-lbs./in.)                                                                 2.8        16.7   8.5                                         ______________________________________                                         .sup.a. poly(2,6dimethyl-1,4-phenylene)ether produced by General Electric     Company                                                                       .sup.b. polyamide 6,6 from duPont                                        

As seen from example 1 and 2 and comparative example A, the addition ofthe polycarboxylic acid to the polyphenylene ether-polyamide compositiongreatly improved the physical properties of such blends as demonstratedby the higher impact strength. Additionally, the compositions were foundto have good compatibility as parts molded from these compositions weredevoid of streaks and or delamination which are often associated withincompatibility. The compositions within the scope of the invention werealso found to have improved elongation, processability and chemicalresistance.

EXAMPLES 3-6

A second series of examples were prepared demonstrating theapplicability of the present invention to rubber modified polyphenyleneether-polyamide blends. These examples were prepared on a twin screwextruder at about 575° F. The specific compositions of these examples aswell as the physical properties thereof were as shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                   B    3        4       5     6                                      ______________________________________                                        polyphenylene ether.sup.a                                                                  49     49       49    49    49                                   polyamide 6,6.sup.b                                                                        41     41       41    41    41                                   citric acid (anhydrous)                                                                    --     0.1      0.25  0.5   --                                   malic acid   --     --       --    --    0.25                                 SEBS.sup.c   10     10       10    10    10                                   Gardner Impact (in.-lbs.)                                                                  18     >320     >320  184   >320                                 Notched Izod (ft.-lb./in.)                                                                 0.8    3.0      2.6   1.5   2.4                                  % Tensile elongation                                                                       8      25       33    15    31                                   ______________________________________                                         .sup.a. poly(2,6diemthyl-1,4-phenylene)ether from General Electric Compan     .sup.b. polyamide 6,6 from duPont                                             .sup.c. Styrene hydrogenated polybutadiene styrene triblock copolymer fro     Shell                                                                    

The results shown in Table 2 clearly demonstrate the benefit andeffectiveness of the polycarboxylic acid in the rubber modifiedpolyphenylene ether-polyamide blends. Additionally, parts prepared fromthe composition within the scope of the present invention were free ofstreaks and/or delamination.

EXAMPLE 7

Two blends of 70% by wt. polyphenylene ether and 30% polyamide 6 wereprepared, one with 0.5 phr citric acid and the other without anypolycarboxylic acid modifier/compatibilizer. The unnotched izod impactstrengths of the latter was only 2.6 ft.-lbs./in. whereas the unnotchedizod impact strength of the composition according to the inventionincreased to 3.2 ft.-lbs./in. This composition also demonstratedimprovement of other physical properties including for example tensileelongation.

EXAMPLES 8-10

A series of polyphenylene ether-polyamide compositions within andoutside of the scope of the present invention were prepared. Allcompositions were prepared on a twin screw extruder by direct additionof ingredients and extruded at approximately 285° C. under vacuum at ascrew speed of 250 rpm. The specific compositions the physicalproperties thereof are shown in Table 3.

                  TABLE 3                                                         ______________________________________                                        Example        C        8       9     10                                      ______________________________________                                        polyphenylene ether.sup.a                                                                    50       50      50    50                                      polyamide 6,6.sup.b                                                                          --       --      50    --                                      polyamide 6,6.sup.c                                                                          50       50      --    --                                      polyamide 6,6.sup.d                                                                          --       --      --    50                                      citric acid (anhydrous) 1       1     1                                       Notched Izod (ft.lb./in.)                                                                       .5    1.0     1.1   1.0                                     Unnotched Izod (ft.lb./in.)                                                                   10*     >11.7   >11.7 >11.7                                   Tensile Yield Strength                                                                         10.8   11.0    11.2  11.0                                    (psi) × 10.sup.3                                                        Tensile Elongation (%)                                                                        7       24      31.5  21                                      ______________________________________                                         .sup.a. polyphenylene ether from General Electric Company                     .sup.b.&c. Fabenyl 45 APBH and R600, respectively from Tubize Polymers SA     Belgium.                                                                      .sup.d. polyamide 6,6 from duPont                                             *one out of six bars shows a value >11.7                                 

These examples demonstrate the improved physical properties associatedwith the use of citric acid in polyphenylene ether-polyamide blends.Specifically, these compositions demonstrated improved compatibility,notched and unnotched izod impact strength, tensile yield strength andelongation as compared to the unmodified composition.

EXAMPLES 11-17

Several compositions were prepared on a twin screw extruder at 285° C.with a screw speed of 300 rpm above. These compositions furtherdemonstrate the applicability of the invention to rubber modified aswell as stabilized and pigmented compositions, at various levels of thepolycarboxylic acid additive. The compositions and properties thereofare shown in Table 4. All amounts are in parts by weight.

Once again these examples demonstrate the excellent properties obtainedby the compositions of the present invention. As seen in examples 13 and14, the loss of impact strength by incorporating the stabilizer additivecan be overcome by increasing the amount of polycarboxylic acid. Thesame is also true for compositions incorporating therein TiO₂ pigment.In general, these compositions had improved physical properties as wellas compatibility as evidenced by the lack of streaks and/or delaminationin molded parts.

                                      TABLE 4                                     __________________________________________________________________________    Example        D 11  12  13  14  15  16  17                                   __________________________________________________________________________    polyphenylene ether.sup.a                                                                    45                                                                              45  45  45  45  45  45  45                                   polyamide 6,6.sup.b                                                                          45                                                                              45  45  45  45  45  45  45                                   citric acid-1-hydrate                                                                          0.35                                                                              0.7 0.35                                                                              0.7 0.35                                                                              0.7 0.35                                 phosphite stabilizer     1   1           1                                    TiO.sub.2                    5   5   5                                        SBS.sup.c      10                                                                              10  10  10  10  10  10  10                                   Unnotched Izod (ft. lb./in.)                                                                   5.3(4)                                                                            6.0(5)                                                                            2.4(0)                                                                            4.3(3)                                                                            3.6(0)                                                                            4.7(2)                                                                            1.9(0)                               Falling Dart Impact (ft. lb.)                                                                14                                                                              162(4)                                                                            >162(4)                                                                           49(0)                                                                             146(2)                                                                            84(0)                                                                             213(2)                                                                            30(0)                                Tensile Yield Strength (psi × 10.sup.3)                                                7.5                                                                             8.4 8.5 8.7 8.4 8.5 8.6 8.5                                  Tensile Elongation (%)                                                                       9.2                                                                             49.7                                                                              57.1                                                                              17.3                                                                              45.9                                                                              30.1                                                                              40.7                                                                              12.2                                 __________________________________________________________________________     .sup.a poly(2,6 dimethyl1,4-phenylene)ether from General Electric Company     .sup.b Fabenyl 45 APBH, water content of 0.3-0.4.                             .sup.c styrenebutadiene-styrene triblock copolymer, Cariflex/KRATON D fro     Shell                                                                         *Numbers in parenthesis represent the number of test parts out of five        tested that did not break at 162 ft. lbs.                                

EXAMPLES 18-21

Compositions in accordance with the present invention were prepared on atwin screw extruder at 295° C. and screw speed 250 rpm. Thesecompositions further comprised an amine compound with and without aphosphite stabilizer. The compositions and the properties thereof areshown in Table 5.

As these examples demonstrate, excellent physical properties areattained by these compositions.

                  TABLE 5                                                         ______________________________________                                        Example       E      18      19    20    21                                   ______________________________________                                        polyphenylene ether.sup.a                                                                   50     50      50    50    50                                   polyamide 6,6.sup.b                                                                         50     50      50    50    50                                   citric acid-1-hydrate                                                                              0.7     0.7   0.7   0.7                                  phosphite stabilizer --      0.35  --    --                                   dibutylamine         --      0.35  0.35  0.7                                  Notched Izod ft. lb./in.                                                                    0.69   1.23    1.0   1.2   1.0                                  Unnotched Izod ft. lb./in.*                                                                        11.7(3) 9.7(0)                                                                              7.0(1)                                                                              11.6(0)                              Tensile Yield strength                                                                      7.8    10.9    10.2  10.8  10.1                                 (×10.sup.3 psi)                                                         Elongation %  5.5    19.7    10.7  14.7  20.8                                 ______________________________________                                         .sup.a polyphenylene ether from General Electric Company                      .sup.b Fabenyl 45APBH from Tubize Polymers S.A. Belgium.                      *Number in parenthesis represents the number of nonbroken bars out of six     tested that did not break at 11.7 ft. lbs.                               

EXAMPLE 22

Two examples of polyphenylene ether-polyamide compositions within andoutside the scope of the present invention were prepared on a twin screwextruder at 285° C. and screw speed of 200 rpm. The specificcompositions and physical properties thereof are shown in Table 6.

These examples further demonstrate the applicability of the presentinvention to other polycarboxylic acids, specifically malic acid.

                  TABLE 6                                                         ______________________________________                                        Example              F      22                                                ______________________________________                                        polyphenylene ether.sup.a                                                                          50     50                                                polyamide 6,6.sup.b  50     50                                                malic acid                  1                                                 Notched Izod ft.lb/in.                                                                             .69    .71                                               Tensile Yield Strength × 10.sup.3 psi                                                        7.8    8.2                                               Tensile Elongation (%)                                                                             5.5    6.5                                               ______________________________________                                         .sup.a.&b. see footnotes Table 3.                                        

EXAMPLES 23-25

Several additional examples were prepared demonstrating various otherpolycarboxylic acid modifiers employable in the practice of the instantinvention. The mono-stearyl citrate employed is from Pfiezer Chemicalsand actually comprises a 22/78 mixture of the mono- and di- stearylesters of citric acid. Acetyl citric acid was prepared inhouse byallowing acetyl chloride to react with the hydroxy group of the citricacid. The carboxylic acid salt, calcium malate, was obtained fromPfaltz-Bauer. The results obtained with these polycarboxylic acids andderivatives were as shown in Table 7.

                  TABLE 7                                                         ______________________________________                                        Example        G      23        24   25                                       ______________________________________                                        polyphenylene ether.sup.a                                                                    70     70        70   70                                       polyamide 6,6.sup.b                                                                          30     30        30   30                                       Monostearyl citrate                                                                          --     1.12      --   --                                       Acetyl citric acid                                                                           --     --        0.5  --                                       Calcium Malate --     --        --   0.5                                      Unnotched Izod 2.8    4.1       6.9  6.9                                      ft.lb/in.                                                                     ______________________________________                                         .sup.a.&b. see footnotes Table 3.                                        

EXAMPLES 26-32

An additional series of examples were prepared, this time demonstratingthe utility of various acid-amides, in the present invention. Theacid-amides were prepared by dissolving the respect acid intetrahydrofuran (THF) and then adding in a drop wise fashion the aminewhile constantly stirring. Depending upon the amine employed, the formedacid-amides precipitated out or formed a highly viscous solution. In theformer case, the precipitate was filtered, washed with clear THF anddried in a vacuum-oven. In the latter case, THF was removed byrotary-evaporation and the remaining paste dried in a vacuum-oven andthe product crystallized. The specific reactants and ratios thereofemployed and the products obtained were as shown in Table 8.

These acid-amides were then used, on an equimolar basis, except in thecase of the malic acid based examples, in accordance with the presentinvention to demonstrate their effectiveness as property enhancers. Thecompositions and the properties obtained were as shown in Tables 9 and10. From Tables 9 and 10 it is apparent that acid-amides derived fromamines having 6 or less carbon atoms are preferred. While acid-amidesprepared from amines having more than 6 carbon atoms appear to havelittle or no effect on physical properties, some improvement in thecolor of the resultant resin was noticed.

                  TABLE 8                                                         ______________________________________                                                                     Reaction Precipitate                                      Polycarboxy-                                                                            Ratio of           formation                               Amine    lic acid  Amine/Acid                                                                              Product  (A/B).sup.c)                            ______________________________________                                        Diethylamine                                                                           citric acid-1-                                                                          1:1       N,N'-diethyl                                                                           A                                                hydrate             citric acid                                                                   amide                                            propylamine                                                                            citric acid-1-                                                                          2:1       N,N'-dipropyl                                                                          A                                                hydrate             citric acid                                                                   amide                                            aniline.sup.a)                                                                         citric acid-1-                                                                          1:1       N-phenyl citric                                                                        B                                                hydrate             acid amide                                       dodecylamine                                                                           citric acid-1-                                                                          1:1       N-dodecyl                                                                              B                                                hydrate             citric acid                                                                   amide                                            dodecylamine                                                                           citric acid-1-                                                                          2:1       N,N'-didodecyl                                                                         B                                                hydrate.sup.b)      citric acid                                                                   amide                                            dodecylamine                                                                           d,1-malic 1:1       N-dodecyl                                                                              B                                                acid.sup.b)         malic acid                                                                    amide                                            ______________________________________                                         .sup.a Purified by vacuum distillation (Fischer Spalt Rohr system).           .sup.b Citric acid/malic acid dissolved at T = 55° C.; reaction        aiso carried out at this temperature                                          .sup.c Ahighly viscous slurry formed; Bprecipitate formed.               

                  TABLE 9                                                         ______________________________________                                        Example   26       27       28    29    30                                    ______________________________________                                        polyphenylene                                                                           50       50       50    50    50                                    ether.sup.a                                                                   polyamide 6,6.sup.b                                                                     50       50       50    50    50                                    citric acid-1-                                                                          0.7      --       --    --    --                                    hydrate                                                                       N-phenyl citric                                                                         --       0.85     --    --    --                                    acid amide                                                                    N-dodecyl citric                                                                        --       --       1.2   --    --                                    acid amide                                                                    N,N'-didodecyl                                                                          --       --       --    1.84  --                                    citric acid amide                                                             N,N'-diethyl                                                                            --       --       --    --    0.825                                 citric acid amide                                                             N,N'-dipropyl                                                                           --       --       --    --    --                                    citric acid amide.sup.c                                                       Unnotched Izod                                                                          >23.4    >23.4    6.74  4.12  >23.4                                 ft.lb./in.                                                                    Notched Izod                                                                            1.09     .94      .64   .67   .81                                   ft.lb./in.                                                                    Tensile Yield                                                                           11063    11165    8845  7685  10875                                 Strength psi                                                                  Tensile   23       8.5      5     4.5   10                                    Elongation, %                                                                 ______________________________________                                         .sup.a.&b. See footnotes a & b, Table 3                                       .sup.c. this acid amide was not tested                                   

                  TABLE 10                                                        ______________________________________                                        Example         H         31       32                                         ______________________________________                                        polyphenylene ether.sup.a                                                                     50        50       50                                         polyamide 6,6.sup.b                                                                           50        50       50                                         malic acid      --        0.5      --                                         N-dodecyl malic acid amide                                                                    --        --       0.5                                        Unnotched Izod, ft.lb./in.                                                                    11.05     16.57    7.06                                       Notched Izod, ft.lb./in.                                                                      .75       .94      .70                                        Tensile Yield Strength psi                                                                    8076      10657    8642                                       Tensile Elongation %                                                                          7.75      19.5     8.0                                        ______________________________________                                         .sup.a.&b. see Table 9                                                   

EXAMPLES 33-45

Two series of compositions were prepared in order to further demonstratethe breadth of the present invention. In these examples, variouspolyamides were evaluated alone and in combination with an additionalmodifier resin.

The specific formulations and the physical properties of thesecompositions were as shown in Table 11 and 12.

                  TABLE 11                                                        ______________________________________                                        Example        I      33     J    34   K    35                                ______________________________________                                        polyphenylene ether.sup.a                                                                    50     50     49   49   50   50                                polyamide 6.sup.b                                                                            50     50     41   41   --   --                                polyamide 12.sup.c                                                                           --     --     --   --   50   50                                citric acid (anhydrous)                                                                      --     0.5    --   0.5  --   0.5                               SEBS.sup.d     --     --     10   10   --   --                                Unnotched izod 2.7    5.9    7.0  >38.0                                                                              3.7  4.3                               impact strength (ft.-lb./in.)                                                 Tensile Elongation %                                                                         --     --     4.1  37.0 --   --                                ______________________________________                                         .sup.a. See footnote a Table 2                                                .sup.b. from Nylon Corporation of America                                     .sup.c. from Hules                                                            .sup.d. Styrene hydrogenated butadiene styrene triblock copolymer from        Shell                                                                    

                                      TABLE 12                                    __________________________________________________________________________                                        Notched Izod                                                                          Tensile                           Example                                                                             Polyamide  Amount                                                                             PPE.sup.a                                                                         CAH.sup.b                                                                          SEBS.sup.c                                                                         ft.lb./in.                                                                            Elongation %                      __________________________________________________________________________    L     polyamide 6,12                                                                           45   45  --   10   0.6     6                                 36    polyamide 6,12                                                                           45   45  0.7  10   2.5     30                                M     polyamide 6/poly-                                                                        45   45  --   10   1.2     10                                37    amide 6,6 copolymer                                                                      45   45  0.7  10   4.1     30                                N     polyamide 12                                                                             45   45  --   10   0.3     4                                 38    polyamide 12                                                                             45   45  0.6  10   0.9     14                                O     polyamide 6                                                                              45   45  --   10   0.3     4                                 39    polyamide 6                                                                              45   45  0.6  10   2.4     30                                P     polyamide 6,6                                                                            45   45  --   10   0.6     5                                 40    polyamide 6,6                                                                            45   45  0.6  10   3.1     38                                Q     polyamide 6,6                                                                            67.5 22.5                                                                              --   10   0.8     22                                41    polyamide 6,6                                                                            67.5 22.5                                                                              0.5  10   2.2     32                                R     polyamide 4,6                                                                            45   45  --   10   0.6     4                                 42    polyamide 4,6                                                                            45   45  0.6  10   4.5     43                                S     polyamide 4,6                                                                            50   50  --   --   0.5     3                                 43    polyamide 4,6                                                                            50   50  0.6  --   1.0     20                                T     polyamide 4,6                                                                            41   49  --   10   0.3     2                                 44    polyamide 4,6                                                                            41   49  0.5  10   4.0     24                                U     polyamide 6,I                                                                            41   49  --   10   0.5     4                                 45    polyamide 6,I                                                                            41   49  0.6  10   4.1     12                                __________________________________________________________________________     .sup.a. see footnote a Table 1                                                .sup.b. citric acid1-hydrate                                                  .sup.c. Styrenehydrogenated butadienestyrene block copolymers            

EXAMPLES 46-67

A series of examples were prepared in order to further demonstrate thebreadth of the present invention as claimed. In this series of examples,various modifier resins known in the art to modify polyamides orpolyphenylene ethers for improved physical properties, especially impactstrength, and/or processability were demonstrated. The various modifierresins employed in these examples were as follows:

Surlyn 9910 and 1706--ionomer resins from E.I. dupont

Primacor 3440--ethylene-comonomer acid (heat stable EAA) from DowChemical

IM 7200--ethylene-propylene rubber/ethylene-propylene-diene monomerrubber from Uniroyal

IM 7565--ethylene-propylene-diene monomer rubber/high densitypolyethylene from Uniroyal

LDPE--low density polyethylene from U.S. Industrial Chemicals

Stereon--styrene butadiene copolymer from Firestone

Paracril--butadiene acrylonitrile copolymer from Uniroyal

HIPS--high impact polystyrene from American Hoechst

EPRgAA--acrylic acid grafted ethylene propylene rubber from Reichold

PEgMA--maleic anhydride grafted polyethylene made in accordance withSwiger et al. U.S. Pat. No. 4,147,740 having 0.75 wt. percent anhydride.

CXA E136--modified ethylene vinyl acetate from E.I. dupont

EPDMgGMA--glycidyl methacrylate grafted EPDM rubber from CopolymersRubber and Chemical Corp.

The specific compositions of each example and the physical propertiesthereof were as shown in Table 13.

                                      TABLE 13                                    __________________________________________________________________________                                 Notched                                                                            Tensile                                          Modifier                Izod Elongation                                  Example                                                                            Resin  Amt.                                                                             PPE.sup.a                                                                        PA6,6.sup.b                                                                       SEBS.sup.c                                                                        CA.sup.d                                                                         ft. lb./in.                                                                        %                                           __________________________________________________________________________    46   Surlyn 1706                                                                           5 49 41  5   0.6                                                                              0.7  29                                          47   Surlyn 9910                                                                           5 49 41  5   0.5                                                                              2.1  22                                          48   Primacor 3440                                                                         5 49 41  5   0.5                                                                              1.6  19                                          49   Primacor 3440                                                                        10 36 54  10  0.5                                                                              1.1  15                                          50   IM 7200                                                                              10 49 41  --  0.5                                                                              1.0  16                                          51   IM 7565                                                                              10 49 41  --  0.5                                                                              2.0  22                                          52   LDPE   10 49 41  --  0.5                                                                              1.5  14                                          V    Stereon                                                                              10 49 41  --  -- 0.2  4                                           53   Stereon                                                                              10 49 41  --  0.5                                                                              1.9  46                                          54   Paracril                                                                             10 49 41  --  0.5                                                                              0.8  15                                          55   HIPS    9 42 40  9   0.5                                                                              2.0  22                                          56   HIPS   10 49 41  --  0.5                                                                              0.8  14                                          57   HIPS   15 44 41  --  0.5                                                                              0.8  9                                           W    HIPS   20 40 40  --  -- 4.2  2.3                                         58   HIPS   20 40 40  --  0.5                                                                              8.6  3.4                                         59   EPRgAA  7 49 41  10   0.75                                                                            1.5  25                                          X    PEgMA  10 36 54  10  -- 0.7  9                                           60   PEgMA  10 36 54  10  0.5                                                                              4.0  41                                          61   PEgMA   5 36 54  10  0.5                                                                              4.1  44                                          62   PEgMA   5 41 49  5   0.6                                                                              2.2  33                                          63   PEgMA  10 41 49  5   0.6                                                                              1.1  27                                          64   PEgMA  10 60 40  5   0.6                                                                              3.5  36                                          65   CXA E136                                                                             10 36 54  10  0.5                                                                              2.6  38                                          Y    EPDMgGMA                                                                             10 45 45  --  -- 0.7  4                                           66   EPDMgGMA                                                                             10 45 45  --  0.7                                                                              1.4  13                                          67   EPDMgGMA                                                                              5 45 45  5   0.7                                                                              2.6  26                                          __________________________________________________________________________     .sup.a & .sup.b see footnotes a & b, Table 2                                  .sup.c see footnote d Table 7                                                 .sup.d citric acid (anhydrous)                                           

EXAMPLES 68-70

Several additional compositions were prepared demonstrating variousembodiments of the present invention. Specifically, these examplesdemonstrate filled compositions, compositions prepared with combinationsof polyamides and super tough polyamides. The specific compositions andthe properties obtained were as shown in Table 14.

Examples 69 and 70 were prepared by precompounding the polyphenyleneether with citric acid and adding the super tough polyamide and glassfiber and polyamide, respectively, through an entry port to the extruderbarrel downstream from the initial feed.

                  TABLE 14                                                        ______________________________________                                        Example        68      Z       69*    70*                                     ______________________________________                                        polyphenylene ether.sup.a                                                                    49      49      50     30                                      polyamide 6.sup.b                                                                            22.5    22.5    --     --                                      polyamide 6,6.sup.c                                                                          22.5    22.5    --     40                                      Zytel ST 801.sup.d                                                                           --      --      50     --                                      citric acid (anhydrous)                                                                      0.5     --      --     0.5                                     citric acid-1-hydrate                                                                        --      --      0.75   --                                      SEBS.sup.e     10      10      --     1                                       Glass fiber    --      --      --     30                                      Stabilizer.sup.f                                                                             --      --      --     0.3                                     Notched Izod ft.lb./in.                                                                      3.5     0.2     3.75   1.7                                     Tensile Elongation, %                                                                        31      2       35.5   7.1                                     Falling Dart ft.lb.                                                                          --      --      31.7   --                                      Tensile Yield Strength psi                                                                   --      --      8076   21885                                   ______________________________________                                         .sup.a. see footnote a Table 2                                                .sup.b.&c. polyamides from duPont                                             .sup.d. super tough, modified polyamide from duPont                           .sup.e. see footnote c Table 2                                                .sup.f. stabilizer package containing hindered phenol antioxidant and         potassium and cuprous salts as heat stabilizers                               *Prepared by precompounding (see text)                                   

EXAMPLES 71-79

Various polyphenylene ether-polyamide compositions were prepared inaccordance with the improved process of the present invention.Specifically, examples within and outside the scope of the presentinvention were prepared by directly compounding all of the ingredients.Examples within the scope of the improved process of the presentinvention were prepared by precompounding the polycarboxylic acid, aloneor in combination with an amine and/or modifier resin, and subsequentlycompounded with the polyamide. The specific formulations and theproperties obtained with each are presented in Table 1.

Table 15 embodies various compositions within and beyond the scope ofthe present invention wherein malic acid comprises the polycarboxylicacid component. Comparative Example AA and Examples 71 and 72demonstrates that while a high level of dibutylamine with malic acidreduces impact strength in the compatibilized composition the samecomposition wherein the malic acid and dibutylamine and polyphenyleneether are precompounded suprisingly enhances impact strength as well aselongation and tensile yield strength. Example 73 demonstratesprecompounding of the polycarboxylic acid amine stabilizer andstyrene-butadiene-styrene triblock copolymer with the polyphenyleneether before blending with polyamide.

Similarly, Table 16 demonstrates once again the utility and theimprovement in precompounding citric acid alone or in combination withthe modifier resin or modifier resin combination prior to compoundingwith the polyamide. The improvement is made clear by comparision ofComparative Examples CC with Examples 74 and 75 as well as comparison ofExamples 77 through 79. In examples 75 and 76 the precompoundcompositions were fed into the extruder as ground particles or ungroundgranules, respectively.

                  TABLE 15                                                        ______________________________________                                        Example         AA     71      72   BB    73                                  ______________________________________                                        polyphenylene ether.sup.a                                                                     50     50      --   45    --                                  polyamide 6,6.sup.b                                                                           --     --      --   45    41                                  polyamide 6,6.sup.c                                                                           50     50      50   --    --                                  d,1-malic acid  --     1       --   --    --                                  dibutylamine    --     1       --   --    --                                  SBS.sup.d       --     --      --   10    --                                  precompound A.sup.e                                                                           --     --      51   --    --                                  precompound B.sup.f                                                                           --     --      --   --    61                                  TiO.sub.2       --     --      --   --    5                                   Notched Izod ft.lb./in.                                                                       .64    .58     .88  1.09  2.4                                 Falling Dart ft.lb.                                                                           --     --      --   14    36.9                                Tensile Yield strength × 10.sup.8 psi                                                   10.6   10.2    11.0 7.5   9.7                                 Tensile Elongation %                                                                          6.5    6.0     23.5 9.2   16.5                                ______________________________________                                         .sup.a,b,c see footnote a,b,c, Table 3                                        .sup.d see footnote c Table 4                                                 .sup.e precompounded composition of 100 pts. polyphenylene ether; 2 pts.      d,1malic acid; 1 pt. dibutylamine                                             .sup.f precompounded composition of 49 pts. polyphenylene ether; 10 pts.      styrenebutadiene-styrene triblock copolymer; 1 pt. dibutylamine and 1 pt.     d,1malic acid                                                            

                                      TABLE 16                                    __________________________________________________________________________    Example     CC  74  75  76   77  78  79                                       __________________________________________________________________________    polyphenylene ether.sup.a                                                                 50  49  24.5                                                                              24.5 9.5 --  39                                       polyamide 6,6.sup.b                                                                       50  41  41  41   41  41  41                                       citric acid-1-hydrate                                                                     --  0.7 --  --   --  --  0.7                                      SBS.sup.c   --  10  10  10   10  --  10                                       HIPS.sup.d  --  --  --  --   --  --  10                                       precompound C.sup.e                                                                       --  --  24.5*                                                                             24.5**                                                                             --  --  --                                       precompound D.sup.f                                                                       --  --  --  --   39.5                                                                              --  --                                       precompound E.sup.g                                                                       --  --  --  --   --  61  --                                       stabilizer  --  --  --  --   --  --  0.3                                      Notched Izod, ft.lb./in.                                                                  .69 2.9 4.5 3.4  4.2 3.4 .56                                      Falling Dart ft.lb.                                                                       --  100 145 155  144 59.7                                                                              --                                       Tensile Yield Strength psi                                                                7815                                                                              8395                                                                              8743                                                                              7641 8511                                                                              9367                                                                              8134                                     Tensile Elongation %                                                                      5.5 78  45  74   39  24  11                                       __________________________________________________________________________     .sup.a,b,c see respective footnotes Table 4                                   .sup.d high impact polystyrene (rubber modified polystyrene)                  .sup.e precompound composition composed of 100 pts. polyphenylene ether,      pt. citric acid1-hydrate and 1 pt. DPK (liquid phosphate)                     .sup.f precompound composition composed of 75 pts. polyphenylene ether, 2     pts. HIPS, and 1 pt. citric acid1-hydrate                                     .sup.g precompound composition composed of 37 pts. polyphenylene ether, 1     pts. HIPS, 10 pts. SBS and 1 pt. citric acid1-hydrate                         *ground                                                                       **granules                                                               

Obviously, other modifications and variations of the present inventionare possible in light of the above teachings. It is therefore to beunderstood that changes may be made in the particular embodiments of theinvention described which are within the full intended scope of theinvention so defined by the appended claims.

We claim:
 1. A novel resin composition comprising:a) one or morepolyphenylene ether resins, b) one or more polyamide resins, and c) acompatibilizer consisting of one or more aliphatic polycarboxylic acidsor derivatives thereof present at a level effective to improvecompatibility and impact strength of the composition, said level ofpolycarboxylic acid or derivative thereof being from about 0.05 to about4% by weight, based on the weight of the total composition, saidaliphatic polycarboxylic acid or derivative thereof being represented bythe formula:

    (R.sup.I O).sub.m R(COOR.sup.II).sub.n (CONR.sup.III R.sup.IV).sub.s

wherein R is a linear or branched chain, saturated aliphatic hydrocarbonof from 2 to 20 carbon atoms; R^(I) is selected from the groupconsisting of hydrogen, and alkyl, aryl, acyl and carbonyl dioxy groupshaving from 1 to 10 carbon atoms; each R^(II) is independently selectedfrom the group consisting of hydrogen, and alkyl or aryl groups havingfrom 1 to 20 carbon atoms; each R^(III) and R^(IV) is independentlyselected from the group consisting of hydrogen, and alkyl or aryl groupshaving from 1 to 10 carbon atoms; m is equal to 1 and (n+s) is greaterthan or equal to 2, and n and s are each greater than or equal to 0;wherein (OR^(I)) is alpha or beta to a carbonyl group and at least 2carbonyl groups are separated by 2 to 6 carbon atoms; and wherein theratio of polyphenylene ether to polyamide is from 5 to 95% by weight ofthe former to 95 to 5% by weight of the latter,said composition furthercomprising from 2 to about 50% by weight based on the total compositionof a modifier resin, and said modifier resin selected from the groupconsisting of vinyl aromatic hydrogenated conjugated diene blockcopolymers, vinyl aromatic partially hydrogenated conjugated diene blockcopolymers, and vinyl aromatic non-hydrogenated conjugated dienetriblock copolymers.
 2. The composition of claim 1 wherein the modifierresin is present in an amount of up to about 35% by weight based on thetotal composition.
 3. The resin composition of claim 1, wherein saidcompatibilizer is selected from the group consisting of anhydrous citricacid, citric acid hydrate, anhydrous malic add, malic acid hydrate,anhydrous agaricic acid, agaricic acid hydrate, and acid amidederivatives of any of the foregoing.
 4. The resin composition of claim 1wherein the ratio of polyphenylene ether to polyamide is from 30 to 70%by weight of the former to 70 to 30% by weight of the latter.
 5. Theresin composition of claim 1, wherein said modifier resin is a vinylaromatic non-hydrogenated conjugated diene triblock copolymer.
 6. Theresin composition of claim 5, wherein said vinyl aromaticnon-hydrogenated conjugated diene triblock copolymer is apolystyrene-polybutadiene-polystyrene triblock copolymer.
 7. The resincomposition of claim 1, wherein said aliphatic polycarboxylic acid iscitric acid hydrate.
 8. The resin composition of claim 1, wherein saidaliphatic polycarboxylic acid is citric acid.
 9. The resin compositionof claim 1, wherein said aliphatic polycarboxylic acid is malic acid.